1. Field of the Invention
The present invention relates to a device for controlling a compressor, and more particularly to an apparatus for controlling a compressor for reversible, dual capacity operation.
2. Description of the Related Art
Economic advantages are provided in the operation of an air conditioning system if the system is capable of operating efficiently at a lowered volumetric displacement on mild days and at a higher volumetric displacement on hot days. Running the system at a lower capacity reduces the power consumption and increases the life of the system.
Typically, multiple compressors or a single dual capacity compressor have been used for this situation. The dual capacity compressor operates two pistons in the forward direction and one piston in the reverse direction. Examples of such a compressor is disclosed in U.S. Pat. No. 4,248,503 and allowed patent application Ser. No. 09/099,013, which are expressly incorporated by reference. A reversible compressor motor is used to run the compressor in the forward or reverse direction. Typically, capacity choice is controlled by a standard mechanical or electronic two stage thermostat.